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408 lines (346 loc) · 12.7 KB
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/*
* Copyright (C) 2011 Apple Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
* OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef DFGGraph_h
#define DFGGraph_h
#if ENABLE(DFG_JIT)
#include "CodeBlock.h"
#include "DFGArgumentPosition.h"
#include "DFGAssemblyHelpers.h"
#include "DFGBasicBlock.h"
#include "DFGNode.h"
#include "MethodOfGettingAValueProfile.h"
#include "RegisterFile.h"
#include <wtf/BitVector.h>
#include <wtf/HashMap.h>
#include <wtf/Vector.h>
#include <wtf/StdLibExtras.h>
namespace JSC {
class CodeBlock;
class ExecState;
namespace DFG {
struct StorageAccessData {
size_t offset;
unsigned identifierNumber;
// NOTE: the offset and identifierNumber do not by themselves
// uniquely identify a property. The identifierNumber and a
// Structure* do. If those two match, then the offset should
// be the same, as well. For any Node that has a StorageAccessData,
// it is possible to retrieve the Structure* by looking at the
// first child. It should be a CheckStructure, which has the
// Structure*.
};
struct ResolveGlobalData {
unsigned identifierNumber;
unsigned resolveInfoIndex;
};
//
// === Graph ===
//
// The dataflow graph is an ordered vector of nodes.
// The order may be significant for nodes with side-effects (property accesses, value conversions).
// Nodes that are 'dead' remain in the vector with refCount 0.
class Graph : public Vector<Node, 64> {
public:
Graph(JSGlobalData& globalData, CodeBlock* codeBlock)
: m_globalData(globalData)
, m_codeBlock(codeBlock)
, m_profiledBlock(codeBlock->alternative())
{
ASSERT(m_profiledBlock);
}
using Vector<Node, 64>::operator[];
using Vector<Node, 64>::at;
Node& operator[](Edge nodeUse) { return at(nodeUse.index()); }
const Node& operator[](Edge nodeUse) const { return at(nodeUse.index()); }
Node& at(Edge nodeUse) { return at(nodeUse.index()); }
const Node& at(Edge nodeUse) const { return at(nodeUse.index()); }
// Mark a node as being referenced.
void ref(NodeIndex nodeIndex)
{
Node& node = at(nodeIndex);
// If the value (before incrementing) was at refCount zero then we need to ref its children.
if (node.ref())
refChildren(nodeIndex);
}
void ref(Edge nodeUse)
{
ref(nodeUse.index());
}
void deref(NodeIndex nodeIndex)
{
if (at(nodeIndex).deref())
derefChildren(nodeIndex);
}
void deref(Edge nodeUse)
{
deref(nodeUse.index());
}
void clearAndDerefChild1(Node& node)
{
if (!node.child1())
return;
deref(node.child1());
node.children.child1() = Edge();
}
void clearAndDerefChild2(Node& node)
{
if (!node.child2())
return;
deref(node.child2());
node.children.child2() = Edge();
}
void clearAndDerefChild3(Node& node)
{
if (!node.child3())
return;
deref(node.child3());
node.children.child3() = Edge();
}
// CodeBlock is optional, but may allow additional information to be dumped (e.g. Identifier names).
void dump();
void dump(NodeIndex);
// Dump the code origin of the given node as a diff from the code origin of the
// preceding node.
void dumpCodeOrigin(NodeIndex, NodeIndex);
BlockIndex blockIndexForBytecodeOffset(Vector<BlockIndex>& blocks, unsigned bytecodeBegin);
PredictedType getJSConstantPrediction(Node& node)
{
return predictionFromValue(node.valueOfJSConstant(m_codeBlock));
}
bool addShouldSpeculateInteger(Node& add)
{
ASSERT(add.op() == ValueAdd || add.op() == ArithAdd || add.op() == ArithSub);
Node& left = at(add.child1());
Node& right = at(add.child2());
if (left.hasConstant())
return addImmediateShouldSpeculateInteger(add, right, left);
if (right.hasConstant())
return addImmediateShouldSpeculateInteger(add, left, right);
return Node::shouldSpeculateInteger(left, right) && add.canSpeculateInteger();
}
bool negateShouldSpeculateInteger(Node& negate)
{
ASSERT(negate.op() == ArithNegate);
return at(negate.child1()).shouldSpeculateInteger() && negate.canSpeculateInteger();
}
bool addShouldSpeculateInteger(NodeIndex nodeIndex)
{
return addShouldSpeculateInteger(at(nodeIndex));
}
// Helper methods to check nodes for constants.
bool isConstant(NodeIndex nodeIndex)
{
return at(nodeIndex).hasConstant();
}
bool isJSConstant(NodeIndex nodeIndex)
{
return at(nodeIndex).hasConstant();
}
bool isInt32Constant(NodeIndex nodeIndex)
{
return at(nodeIndex).isInt32Constant(m_codeBlock);
}
bool isDoubleConstant(NodeIndex nodeIndex)
{
return at(nodeIndex).isDoubleConstant(m_codeBlock);
}
bool isNumberConstant(NodeIndex nodeIndex)
{
return at(nodeIndex).isNumberConstant(m_codeBlock);
}
bool isBooleanConstant(NodeIndex nodeIndex)
{
return at(nodeIndex).isBooleanConstant(m_codeBlock);
}
bool isFunctionConstant(NodeIndex nodeIndex)
{
if (!isJSConstant(nodeIndex))
return false;
if (!getJSFunction(valueOfJSConstant(nodeIndex)))
return false;
return true;
}
// Helper methods get constant values from nodes.
JSValue valueOfJSConstant(NodeIndex nodeIndex)
{
return at(nodeIndex).valueOfJSConstant(m_codeBlock);
}
int32_t valueOfInt32Constant(NodeIndex nodeIndex)
{
return valueOfJSConstant(nodeIndex).asInt32();
}
double valueOfNumberConstant(NodeIndex nodeIndex)
{
return valueOfJSConstant(nodeIndex).asNumber();
}
bool valueOfBooleanConstant(NodeIndex nodeIndex)
{
return valueOfJSConstant(nodeIndex).asBoolean();
}
JSFunction* valueOfFunctionConstant(NodeIndex nodeIndex)
{
JSCell* function = getJSFunction(valueOfJSConstant(nodeIndex));
ASSERT(function);
return jsCast<JSFunction*>(function);
}
static const char *opName(NodeType);
// This is O(n), and should only be used for verbose dumps.
const char* nameOfVariableAccessData(VariableAccessData*);
void predictArgumentTypes();
StructureSet* addStructureSet(const StructureSet& structureSet)
{
ASSERT(structureSet.size());
m_structureSet.append(structureSet);
return &m_structureSet.last();
}
StructureTransitionData* addStructureTransitionData(const StructureTransitionData& structureTransitionData)
{
m_structureTransitionData.append(structureTransitionData);
return &m_structureTransitionData.last();
}
CodeBlock* baselineCodeBlockFor(const CodeOrigin& codeOrigin)
{
return baselineCodeBlockForOriginAndBaselineCodeBlock(codeOrigin, m_profiledBlock);
}
ValueProfile* valueProfileFor(NodeIndex nodeIndex)
{
if (nodeIndex == NoNode)
return 0;
Node& node = at(nodeIndex);
CodeBlock* profiledBlock = baselineCodeBlockFor(node.codeOrigin);
if (node.hasLocal()) {
if (!operandIsArgument(node.local()))
return 0;
int argument = operandToArgument(node.local());
if (node.variableAccessData() != at(m_arguments[argument]).variableAccessData())
return 0;
return profiledBlock->valueProfileForArgument(argument);
}
if (node.hasHeapPrediction())
return profiledBlock->valueProfileForBytecodeOffset(node.codeOrigin.bytecodeIndexForValueProfile());
return 0;
}
MethodOfGettingAValueProfile methodOfGettingAValueProfileFor(NodeIndex nodeIndex)
{
if (nodeIndex == NoNode)
return MethodOfGettingAValueProfile();
Node& node = at(nodeIndex);
CodeBlock* profiledBlock = baselineCodeBlockFor(node.codeOrigin);
if (node.op() == GetLocal) {
return MethodOfGettingAValueProfile::fromLazyOperand(
profiledBlock,
LazyOperandValueProfileKey(
node.codeOrigin.bytecodeIndex, node.local()));
}
return MethodOfGettingAValueProfile(valueProfileFor(nodeIndex));
}
bool needsActivation() const
{
#if DFG_ENABLE(ALL_VARIABLES_CAPTURED)
return true;
#else
return m_codeBlock->needsFullScopeChain() && m_codeBlock->codeType() != GlobalCode;
#endif
}
// Pass an argument index. Currently it's ignored, but that's somewhat
// of a bug.
bool argumentIsCaptured(int) const
{
return needsActivation();
}
bool localIsCaptured(int operand) const
{
#if DFG_ENABLE(ALL_VARIABLES_CAPTURED)
return operand < m_codeBlock->m_numVars;
#else
return operand < m_codeBlock->m_numCapturedVars;
#endif
}
bool isCaptured(int operand) const
{
if (operandIsArgument(operand))
return argumentIsCaptured(operandToArgument(operand));
return localIsCaptured(operand);
}
bool isCaptured(VirtualRegister virtualRegister) const
{
return isCaptured(static_cast<int>(virtualRegister));
}
JSGlobalData& m_globalData;
CodeBlock* m_codeBlock;
CodeBlock* m_profiledBlock;
Vector< OwnPtr<BasicBlock> , 8> m_blocks;
Vector<Edge, 16> m_varArgChildren;
Vector<StorageAccessData> m_storageAccessData;
Vector<ResolveGlobalData> m_resolveGlobalData;
Vector<NodeIndex, 8> m_arguments;
SegmentedVector<VariableAccessData, 16> m_variableAccessData;
SegmentedVector<ArgumentPosition, 8> m_argumentPositions;
SegmentedVector<StructureSet, 16> m_structureSet;
SegmentedVector<StructureTransitionData, 8> m_structureTransitionData;
BitVector m_preservedVars;
unsigned m_localVars;
unsigned m_parameterSlots;
private:
bool addImmediateShouldSpeculateInteger(Node& add, Node& variable, Node& immediate)
{
ASSERT(immediate.hasConstant());
JSValue immediateValue = immediate.valueOfJSConstant(m_codeBlock);
if (!immediateValue.isNumber())
return false;
if (!variable.shouldSpeculateInteger())
return false;
if (immediateValue.isInt32())
return add.canSpeculateInteger();
double doubleImmediate = immediateValue.asDouble();
const double twoToThe48 = 281474976710656.0;
if (doubleImmediate < -twoToThe48 || doubleImmediate > twoToThe48)
return false;
return nodeCanTruncateInteger(add.arithNodeFlags());
}
// When a node's refCount goes from 0 to 1, it must (logically) recursively ref all of its children, and vice versa.
void refChildren(NodeIndex);
void derefChildren(NodeIndex);
};
class GetBytecodeBeginForBlock {
public:
GetBytecodeBeginForBlock(Graph& graph)
: m_graph(graph)
{
}
unsigned operator()(BlockIndex* blockIndex) const
{
return m_graph.m_blocks[*blockIndex]->bytecodeBegin;
}
private:
Graph& m_graph;
};
inline BlockIndex Graph::blockIndexForBytecodeOffset(Vector<BlockIndex>& linkingTargets, unsigned bytecodeBegin)
{
return *WTF::binarySearchWithFunctor<BlockIndex, unsigned>(linkingTargets.begin(), linkingTargets.size(), bytecodeBegin, WTF::KeyMustBePresentInArray, GetBytecodeBeginForBlock(*this));
}
} } // namespace JSC::DFG
#endif
#endif